zsh: the shell as a module — package, the mesh's ~/.zshrc block, the login-shell seat and execute

The first module of the operator's environment (novox/hq to-be 37 §1, ADR 0173,
0176). A package, the mesh's default configuration as a block inside the
account's ~/.zshrc so the operator's own lines around it survive every push
(ADR 0174 as the host's `into: block` realises it), a `user` shape that makes
zsh the account's login shell, the `login-shell` seat declared with its one
verb, and a tools bundle: `execute` under the seat's name, `zsh_config` under
the module's. No container, no process: the tools are served by the node tools
runtime (ADR 0175), which does not exist yet — the bundle builds and the
manifest registers ahead of it. `module check` passes; the tools type-check
against the SDK.

Two things the manifest cannot yet say, left for the controller: the `user`
shape applies wherever the module is assigned, not only where it holds the
seat; and the runtime learns the account from MESH_OPERATOR_ACCOUNT, which
nothing sets yet.

modules/zsh/tsconfig.json

@@ -0,0 +1,14 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "noEmit": true
+  },
+  "include": [
+    "tools/index.ts"
+  ]
+}